Neuroscientists and neurosurgeons at the EPFL/CHUV/UNIL, Inserm and the University of Bordeaux have designed a neuroprosthetic intended to correct walking disorders associated with Parkinson’s disease. In a study published in Nature Medicine, the scientists set out in detail the process of developing the neuroprosthetic that has allowed a first patient with Parkinson’s to be treated, enabling him to walk comfortably, confidently and without falling.
Disabling walking disorders occur in around 90% of persons who are at an advanced stage of Parkinson’s disease. These walking disorders are often resistant to the treatments that are currently available. Marc, 62, has lived with Parkinson’s for almost three decades. Dopamine and then the deep brain stimulation he received in 2004 dealt with his tremors and stiffness. More recently, he developed serious walking disorders which did not respond to dopamine or brain stimulation. “I practically could not walk anymore without falling frequently, several times a day. In some situations, such as entering a lift, I’d trample on the spot, as though I was frozen there, you might say.”
Electric stimulation of the spinal cord
“The idea of developing a neuroprosthetic that stimulates the spinal cord electrically to harmonise the procedure and correct locomotor disorders in patients with Parkinson’s is the result of several years of research on the treatment of paralysis due to spinal-cord injuries,” explains Grégoire Courtine, professor of neuroscience at EPFL, the Lausanne University Hospital (CHUV) and UNIL. Unlike conventional treatments for Parkinson’s which target the regions of the brain directly affected by the loss of dopamine-producing neurons, this neuro- prosthetic targets the spinal area responsible for activating leg muscles while walking, which is not seemingly directly affected by Parkinson’s disease.
“It is impressive to see how by electrically stimulating the spinal cord in a targeted manner, in the same way as we have done with paraplegic patients, we can correct walking disorders caused by Parkinson’s disease”, says Jocelyne Bloch, neurosurgeon and professor at the CHUV, UNIL and EPFL, and co-director of the .NeuroRestore centre with Grégoire Courtine.
The implantation of this neuroprosthetic in a patient would not have been possible without the collaboration of Dr Erwan Bezard, neuroscientist at Inserm, affiliate at the CNRS and the University of Bordeaux, who has dedicated his career to understanding neurodegenerative diseases. His expertise in preclinical models of Parkinson’s disease was essential to correctly produce the technological and conceptual developments required for clinical application in human beings.